Apparatus for preparing cellulose xanthate



Feb. 12, 1957 ToMlzo SAI-ro APPARATUS FOR PREPARING CELLULOSE XANTHATE 3 Sheets-Sheet l Filed Dec. 13, 1952 JNVENTOR. TOM/Zo S14/ro i ASEAN* 4 @afi n @ygr- I BY Feb. 12, 1957 ToMlzo SAITO APPARATUS FOR PREPARING CELLULOSE XANTHATE Filed Dec. 13. 1952 3 Sheets-Sheet 2 INVENTOR. 7/14/20 Sfr/70 Feb. l2, 1957 ToMlzo sAlTo 2,781,252

APPARATUS FOR PREPARING CELLULOSE XANTHATE Filed Deo. 15, 1952 3 Sheets-Sheet 5 IN V EN TOR.

APPARATUS FOR PREPARING CELLULOSE XANTHATE Tomizo Saito, Shinagawa-ku, Tokyo, Japan Application December 13, 1952, Serial No. 325,751 4 Claims. (Cl. 231-285) The present invention relates to apparatus for preparing cellulose xanthate consisting principally of a vacuum chamber for containing alkali cellulose and hydrogen bisulphide for reaction therewith, and more particularly aims to provide improvements relative to feed and exhaust pipes and safety-valve means.

A principal object of this invention is to provide an apparatus adapted to insure an exact feeding of alkali cellulose as a consequence of insuring a prevention of any sprinkling of the alkali cellulose during charging;

this object being attained incidental to the provision, in combination with a feed pipe incorporating a lead pipe, of a cylinder liner inserted within and slidably movable up and down in the said feed pipe toward and away from a station at which a cover plate is adapted to be placed for tightly closing the vacuum chamber when, following completion of the feeding of a charge of alkali cellulose while said cover plate is temporarily away from said station. The Iarrangement is such that, with the cylinder liner capable of being sufficiently lowered to have its bottom portion project suitably down into the vacuum chamber, said cylinder lliner can be readily positioned to insure that during the feeding of a charge of alkali cellulose any sprinkling thereof is prevented. The arrangement is further such that, after return of said cover plate to its said station following said feeding `and a subsequent ascent of ythe cylinder liner to an elevated position in the lead pipe, the cylinder liner can be readily lowered once again, but this time t-o a less extent than required to have its bottom portion project downwardly into the vacuum chamber. Such lesser descent of the cylinder liner is for bringing its bottom end down tight against the top of said cover plate and for causing the cylinder liner to exert pressure thereon to seal the vacuum inside said chamber.

Another principal object of the present invention is to provide an apparatus having a vacuum chamber for use in the production of cellulose xanthate, with said apparatus including means for preventing the absorption or loss of alkali cellulose from the chamber while the latter is being evacuated, and with said means incorporating an exhaust pipe and a filter therein.

A further object of this invention is to provide a vacuum xanthator adapted to avoid explosion of the xanthator drum by the provision of a safety valve having a spring equipped conical valve, at substantially the center on the top of xanthator drum, in which said safety valve is readily operable even by a weak explosion, and further adapted after explosion to prevent the discharge of bisulfide gas out of the drum.

yFurther objects, features and advantages of the present invention will be apparent from the following descriptions in reference to the embodiment shown in the accompanying drawings of which Fig. 1 is an oblique view of the whole embodiment;

lFig. 2 an elevation thereof with a part removed;

Fig. 3 a sectional front view of a feed valve for cellulose;

IFig. 4 a front view of an exhaust pipe, with a part thereof being removed;

Fig 5 a sectional plan view of Fig. 4;

Fig. 6 an elevation of a safety valve; and

fFig. 7 a plan view of Fig. 6.

The detailed explanation will be given in reference to the accompanying drawings as follows:

Referring to Figs. l and 2, a feed pipe 5 for alkali cellulose is provided on one side of the top wall 4 of an xanthat-or drum 3 in which agitator vanes are lixed on rotary shafts 1 and 2. A cylinder liner 6 (Fig. 3) inserted in the feed pipe 5, is movable up and down inside latter. A worm 10 is secured on one side of feed pipe 5, rotatable through a handle 7, worm 8 and worm gear 9. The worm 10 is brought -to engage with a rack 11 having worm type teeth and provided outside of the cylinder liner 6. Packing rings 12 are provided on the upper external wall of the cylinder liner 6. A lead pipe 13 is rotatably inserted inside the feed pipe 5. A llange 14 is provided around the middle external periphery of the lead pipe 13. The flange 14 is held by the upper end 15 of feed pipe 5. A ring 17 having screws 16 screwed in the upper end 15 of the feed pipe 5 is provided on the upper surface of said flange 14, in order that the lead pipe 13 may not be detached from the feed pipe 5 when the lead pipe 13 is rota-ted on the llange 14.

A flanged valve 18 is provided around the external periphery of the lower portion of said cylinder liner 6. A packing ring 21 is inserted in the upper portion 20 of the bottom section 19 for the said feed pipe 5. A coverplate 23 having a packing ring 22 on its top surface is adapted to rest on the packing ring 21 except while alkali cellulose is being fed, during which time the coverplate 23 is removed as described hereinafter. With cylinder liner 6 moved down part of the way its lower end 24 is pressed on the packing ring 22 on the top of cover-plate 23, the latter beingI close against the packing ring 2l of seat face 20 to shut the inlet 19 and thereby keep vacuum inside the xanthator drum 3. And on the external wall of cylinder liner is provided a key way 25, along which is inserted a pin 26 secured to the lead pipe 5, adapted to prevent the rotation of cylinder liner 6, while being moved up and down by the rotation of ythe worm 10 through rack teeth 11. On the other hand, the flange valve 18, following removal of the cover plate 23, may be brought 'tight against the packing ring 21 of sea-t face 20 Ato ensure air-tightness between the cylinder liner 6 and the feed pipe 5, when the cylinder liner 6 is moved down all the way, at which time its lower end 24 ente-rs the xanthator drum 3 through the bottom section 19, in order to feed alkali cellulose.

Opening 27 shown in Fig. 3 with a broken line is provided to permit the insertion and removal of the coverplate 23. Thus when inlet 19 is to be closed, cover-plate 23 having packing ring 22 thereon may be inserted through opening 27 as for instance by -a handle thereon provided at opening 27, after which the cylinder liner 6 may be moved down part of the way and press on the packing ring 22 with its lower end 24 as aforementioned. When it is desired t-o feed alkali cellulose to the Xanthator drum 3 through inlet 19 `the cover-plate 23 and packing ring 22 thereon can be withdrawn through the opening 27 by means of said handle thereon to permit the cylinder liner 6 to be moved down all the way so that its lower end 24 can enter the inlet 19 and into the Xanthator drum 3 as described above.

In feeding alkali cellulose in the xanthator drum 3, first the handle 7 is rotated after the cover-plate 23 has been withdrawn together with the packing ring 22 thereon through opening 27, and thereby worm S and worm gear 9 are revolved, and with them worm 10. The cylinder liner 6 is thus made to slide down, through rack Patented Feb. 1.2, 1957 teeth 11 being in mesh relation with the said worm 10, and the ylower end 24 of cylinder liner 6 descends as just above described into the xanthator drum 3.

Thereby alkali cellulose is capable of being fed exactly into the xanthator, without `any sprinkling of Ialkali cellulose, and after the fee-ding, no alkali cellulose is remained adhered to the bottom section i9 of Vfeed pipe 5. Moreover, the flange valve i8 comes in close contact `with the packing 21, when the cylinder liner 6 is inserted, to ensure the air-tightness between the upper portion of cylinder liner 6 and any feed pipe. Thus, `the leakingout of the alkali cellulose is prevented. ln addition, there is much convenience in the feeding of cellulose, in `that the direction of inclination of the upper feeding spout portion of the lead pipe `13 can be changed by freely -rotating Ithe lead pipe 13. And when the bottom se-ction 19 of feed pipe 5 is to be closed tightly, the coverplate 23, after raising the cylinder liner 6, is inserted through the opening 27, and `then Yis pressed against the packing ring 2i of the bottom 2d bylowering the cylinder liner 6. The air-tightness inside the xanthator drum 3 is thereby ensured, and accordingly a Vhigh vacuum inside of lthe xanthator drum may be maintained.

On the top of xanthator drum 3, is provided an exhaust pipe 2S (see Figs. 4 and 5), in which is placed a screen or filter means 30 consisting of a metal gauze, etc., rotating around a spindle 29 4as an axial line, above which is provided an exhaust valve 31, on one side of which is provided a bifureated pipe 32, on the upper ends of which an exhaust valve 33 and a feed valve 34 are provided respectively. in order to evacuate inside of the xanthator drum 3, the exhaust valve 33 is opened and exhausting is carried out by means of a vacuum pump through the exhaust pipe 28. And when the air is intended to lead in the xanthator drum 3, the feed valve 34 is used. Besides, the suction of alkali cellulose liable to occur inside the xanthator drum 3 during the exhaustion may be prevented by means of the filter means 3i).

At the center on the top of xanthator drum 3, as shown in Figs. 6 and 7, a safety valve 37 is provided having a conical valve body 36 loaded by a spring 35. Above the said safety valve 37' is provided a cover 38, having offset therefrom a spindle 39 carrying 4a gear wheel dit. A balance weight d3 is secured to the handle rod 42 of a segmental piece 41 in mesh relation with the said Wheel 40. On the other side of cover 36 is secured a stophook 45 having a Ihandle 44. The said stop-hook 45 is brought then to engage with the halting recess 47 of a projecting cylinder 46 -so that the said -cover 38 may be xed. And when the pressure in the xanthator drum 3 exceeds the predetermined height, the pressure will be reduced in opening the safety valve 37 in order to avoid damages due to the explosion. And at the same time the evolution from the xanthator drum 3 of bisulde gas resulting from the explosion is prevented. When the cover 38 is to be opened, the stop-hook 45 is released with the handle d4 from the engagement with the recess 47 in the projecting cylinder ,46. The handle rod 42 now can be lowered; which movement sets in revolution the segmental piece 'di and gear wheel fail, with the latter rotating clockwise shown in Fig. 6. Thus the cover- 38 may be opened readily. The opened state of the cover 38 is maintained by the balancing weight d3. When closing the cover 33, the handle 42 is raised and, the segmental piece 4l and gear wheel 4t) are rotated in the reverse direction to thereby close the cover 38. rilhen, the cover 38 m-ay be locked readily, and the handle rod 42 is kept in the raised position.

What I claim is:

l. An apparatus for preparing cellulose xanthate, comprisinga housing providing a vacuum chamber for containing alkali cellulose and hydrogen bisulphide for reaction therewith. to produce cellulose xanthate, a feed pipe mounted `on the upper portion of said housing for delivering thereto a charge of alkali cellulose, an upper pipe d rotatably mounted in the upper port-ion of ysaid feed pipe, a cylinder liner inside said feed pipe and slidably movable up and down therein, said housing having a top feed inlet to the vacuum chamber, and said cylinder liner being adjustable in the feed pipe to project the lower end thereof down through said inlet whereby to feed a charge of -alkali cellulose into the vacuum chamber packing rings surrounding the cylinder liner in contact therewith at its upper portion and in contact with the intern-al periphery of the feed pipe, the cylinder liner intermediate its ends including an external flange having a bottom annular face acting as a valve member in cooperation with another packing ring mounted on la bottom portion of said feed pipe adjacent said inlet when said lower end of said cylinder liner is projected down through said inlet, a closing plate movable to overlie said inlet and rest on said other packing ring at a time other than when a charge of alkali cellulose is being fed into the vacuum chamber through said feed pipe and cylinder liner, still another packing ring on the upper side of said plate and so arranged thereon that, with said plate positioned to cover said inlet, said cylinder liner can be adjusted in said feed pipe to move said lower end thereof into tight engagement with the last-named packing ring thereby to seal closed said feed inlet, an exhaust cylinder for said chamber, a filter means coacting with said exhaust cylinder to prevent alkali cellulose from being sucked out of the said vacuum chamber during exhaustion of the latter, said exhaust cylinder being equipped with valves, 'and a plurality of shafts eac-h `rotatable to open or close a particular one of said valves.

2. An apparatus for preparing cellulose xanthate, comprising a housing providing a vacuum chamber for containing alkali cellulose and hydrogen bisulphide for reaction therewith to produce cellulose xanthate, a feed pipe mounted on the upper portion of said housing for delivering thereto a charge of alkali cellulose, an upper pipe rotatably mounted yin the upper portion of said feed pipe, a cylinder -liner inside said feed pipe and slidably movable up and down therein, said housing having a top feed inlet to the vacuum chamber, and said cylinder liner being adjustable in the feed pipe to project the lower end thereof down through said inlet whereby to feed a charge of alkali cellulose into the vacuum chamber, packing rings surrounding the cylinder liner in contact therewith at its upper portion and in contact with the internal periphery of the feed pipe, the cylinder liner intermediate its ends including an external flange having a bottom annular face acting as a valve member in cooperation with another packing ring mounted on a bottom portion of said feed pipe adjacent said inlet when said lower end of said cylinder liner is projected down through said inlet, a closing plate movable to overlie said inlet and rest on said other packing ring at a time other than when a charge of alkali cellulose is being fed into the vacuum chamber through said feed pipe and cylinder liner, still another' packing ring on the upper side of said plate and so arranged thereon that, with said plate positioned to cover said inlet, said cylinder liner can be adjusted in said feed pipe to move said lower end thereof into tight engagement with the last-named packing ring thereby to seal closed said feed inlet, an exhaust cylinder for said chamber having a metal gauge screen therein to prevent alkali cellulose from being sucked out of the said vacuum chamber during exhaustion of the latter, a spindle carrying said screen whereby the latter may be rotated in the exhaust cylinder, said exhaust cylinder beyond said screen having a bifurcated extension, a vacuum valve in one limb of said extension, and a feed valve in the other limb of said extension.

3. An apparatus for preparing cellulose xanthate, comprising a housing providing a vacuum chamber for containing alkali cellulose and hydrogen bisulphide for reaction therewith to produce cellulose xanthate, a feed pipe mounted on the upper portion of said housing for delivering thereto a charge of alkali cellulose, an upper pipe rotatably mounted in the upper portion of said feed pipe, a cylinder liner inside said feed pipe and slidably movable up and down therein, said housing having a top feed inlet to the vacuum chamber, and said cylinder liner being adjustable in the feed pipe to project the lower end thereof down through said inlet whereby to feed a charge of alkali cellulose into the vacuum chamber, packing rings surrounding the cylinder liner in contact therewith at its upper portion and in contact with the internal periphery of the feed pipe, the cylinder liner intermediate its ends including an external flange having a bottom annular face acting as a valve member in cooperation with another packing ring mounted on a bottom portion of said feed pipe adjacent said inlet when said lower end of said cylinder liner is projected down through said inlet, a closing plate movable to overlie said inlet and rest on said other packing ring at a time other than when a charge of alkali cellulose is being fed into the vacuum chamber through said feed pipe and cylinder liner, still another' packing ring on the upper side of said plate and so arranged thereon that, with said plate positioned to cover said inlet, said cylinder liner can be adjusted in said feed pipe to move said lower end thereof into tight engagement with the last-named packing ring thereby to seal closed said feed inlet, an exhaust cylinder for said chamber having a metal gauge screen therein to prevent alkali cellulose from being sucked out of the said vacuum chamber during exhaustion of the latter, a spindle carrying said screen whereby the latter may be rotated in the exhaust cylinder, said exhaust cylinder beyond said screen having a bifurcated extension, a vacuum valve in one limb of said extension, and a feed valve in the other limb of said extension, a safety valve substantially at the top center of said housing, said valve having a casing which near its bottom opens into the vacuum chamber, the valve member of said safety valve being conical, a spring for loading the last-named valve member, a cover for the safety valve above its valve member, a shaft carried by and oifset from said cover, a toothed gear carried by said shaft, a rod-like handle pivotally mounted on the safety valve casing, a toothed gear segment xed on the handle and meshing with said gear, a balance weight on the handle, and means for locking the cover closed including a pivotally mounted hook having a handle.

4. An apparatus for preparing cellulose xanthate, comprising a housing providing a vacuum chamber for containing alkali cellulose and hydrogen bisulphide for reaction therewith to produce cellulose xanthate, a downwardly extending feed pipe mounted on the upper portion of said housing for delivering thereto a charge of alkali cellulose, a liner pipe inside the first-named pipe and slidably movable up and down therein, said liner pipe being adjustable to project a portion thereof into said vacuum chamber whereby to feed a charge of alkali cellulose thereinto, an exhaust cylinder for said chamber, a filter means coacting with said exhaust cylinder to prevent alkali cellulose from being sucked out of the said vacuum chamber during exhaustion of the latter, and a safety valve operable to allow escape of bisulphide gas from said vacuum chamber when said gas builds up in said chamber to a pressure dangerous to continued integrity of said housing, said safety valve being substantially at the top center of said housing and having a casing which near its bottom opens into the vacuum chamber, a conical valve member, a spring for loading the lastnamed valve member, a cover for the safety valve above its valve member, a shaft carried by and oset from said cover, a toothed gear carried by said shaft, a rodlike handle pivotally mounted on the safety valve casing, a toothed gear segment xed on the handle and meshing with said gear, a balance weight on the handle, and means for locking the cover closed including a pivotally mounted hook having a handle.

References Cited in the tile of this patent UNITED STATES PATENTS 1,676,691 Fresk Apr. 28, 1931 1,834,605 Dassonville Dec. 1, 1931 1,848,095 Bartlett Mar. 8, 1932 1,947,852 Jewett Feb. 20, 1934 

1. AN APPARATUS FOR PREPARING CELLULOSE EXANTHATE, COMPRISING A HOUSING PROVIDING A VACUUM CHAMBER FOR CONTAINING ALKALI CELLULOSE AND HYDROGEN BISULPHIDE FOR REACTION THEREWITH TO PRODUCE CELLULOSE XANTHATE, A FEED PIPE MOUNTED ON THE UPPER PORTION OF SAID HOUSING FOR DELIVERING THERETO A CHARGE OF ALKALI CELLULOSE, AN UPPER PIPE ROTATABLY MOUNTED IN THE UPPER PORTION OF SAID FEED PIPE, A CYLINDER LINER INSIDE SAID FEED PIPER AND SLIDABLY MOVABLE UP AND DOWN THEREIN, SAID HOUSING HAVING A TOP FEED INLET TO THE VACUUM CHAMBER, AND SAID CYLINDER LINER BEING ADJUSTABLE IN THE FEED PIPE TO PROJECT THE LOWER END THEREOF DOWN THROUGH SAID INLET WHEREBY TO FEED A CHARGE OF ALKALI CELLULOSE INTO THE VACUUM CHAMBER PACKING RINGS SURROUNDING THE CYLINDER LINER IN CONTACT THEREWITH AT ITS UPPER PORTION AND IN CONTACT WITH THE INTERNAL PERIPHERY OF THE FEED PIPE, THE CYLINDER LINER INTERMEDIATE ITS ENDS INCLUDING AN EXTERNAL FLANGE HAVING A BOTTOM ANNULAR FACE ACTING AS A VALVE MEMBER IN COOPERATION WITH ANOTHER PACKING RING MOUNTED ON A BOTTOM PORTION OF SAID FEED PIPE ADJACENT SAID INLET WHEN SAID LOWER END OF SAID CYLINDER LINER IS PROJECTED DOWN THROUGH SAID INLET, A CLOSING PLATE MOVABLE TO OVERLIE SAID INLET AND REST ON SAID OTHER PACKING RING AT A TIME OTHER THAN WHEN A CHARGE OF ALKALI CELLULOSE IS BEING FED INTO THE VACUUM CHAMBER THROUGH SAID FEED PIPE AND CYLINDER LINER, STILL ANOTHER PACKING RING ON THE UPPER SIDE OF SAID PLATE AND SO ARRANGED THEREON THAT, WITH SAID PLATE POSITIONED TO COVER SAID INLET, SAID CYLINDER LINER CAN BE ADJUSTED IN SAID FEED PIPE TO MOVE SAID LOWER END THEREOF INTO TIGHT ENGAGEMENT WITH THE LAST-NAMED PACKING RING THEREBY TO SEAL CLOSED SAID FEED INLET, AN EXHAUST CYLINDER FOR SAID CHAMBER, A FILTER MEANS COACTING WITH SAID EXHAUSE CYLINDER TO PREVENT ALKALI CELLULOSE FROM BEING SUCKED OUT OF THE SAID VACUUM CHAMBER DURING EXHAUSTION OF THE LATTER, SAID EXHAUST CYLINDER BEING EQUIPPED WITH VALVES, AND A PLURALITY OF SHAFTS EACH ROTATABLE TO OPEN OR CLOSE A PARTICULAR ONE OF SAID VALVES. 